Method and apparatus for transmitting/receiving broadcasting-communication data

ABSTRACT

A broadcasting-communication data receiving apparatus for receiving mixed signals including original signals and additional signals. The apparatus includes a receiver for receiving the mixed signals and outputting mixed signals of a predetermined band, a first demodulator for receiving the mixed signals of the predetermined band and generating baseband mixed signals, an original data generator for receiving the baseband mixed signals and generating original data, an original signal generator for receiving the original data and generating baseband original signals, a modulator for receiving the baseband original signals and generating original signals of a predetermined band, a subtractor for subtracting the original and mixed signals of the predetermined band to thereby generate additional signals of a predetermined band, a second demodulator for receiving the additional signals of the predetermined band and generating baseband additional signals, and an additional data generator for receiving the baseband additional signals and generating additional data.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of co-pending applicationSer. No. 12/994,827 filed on Nov. 26, 2010, and claims priority under 35U.S.C. §119 of Korean Patent Application Nos. 10-2008-0050044 filed onMay 29, 2008 and 10-2009-0046540 filed on May 27, 2009, the disclosuresof which are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a method and apparatus fortransmitting/receiving broadcasting-communication data.

BACKGROUND ART

Communication technology has made a progress by being divided into acable transmission technology mainly providing a data service and awireless transmission technology focusing on a speech service. Recentprogress in high-speed wireless transmission technology and cablenetwork infrastructure contributes to the continuous development ofcable and wireless integrated technologies that can provide a dataservice while securing mobility. The cable-wireless integratedtechnology can provide users with a variety of services with no regionalrestriction.

Meanwhile, broadcasting technology is undergoing a dramatic change fromanalog scheme to digital scheme. The change in the broadcastingtechnology has made it possible to provide users with even more abundantsorts of services such as bi-directional broadcasting service andadditional services as well as typical real-time broadcasting services.A broadcasting system occupies one axis of information infrastructure incombination with a communication system, such as cable and wirelessinternet. A broadcasting system and a communication system, which usedto be separate systems independent from each other, are organicallycombined with each other and make advances.

Generally, broadcasting-communication system exists in the form ofdiverse systems developed to provide diverse services. The datatransmission rate of the broadcasting-communication system is determinedaccording to the standard of a corresponding technological area. Forexample, the standard data transmission rate of the Advanced TerrestrialSystems Committee (ATSC) 8-Vestigial Sideband (VSB) is 19.39 Mbps at 6MHz band, whereas the standard data transmission rate of Digital VideoBroadcasting-Terrestrial (DVB-T) ranges from at least 4.354 Mbps up to27.710 Mbps at 7 MHz band. Also, the standard data transmission rate ofthe Terrestrial-Digital Multimedia Broadcasting (T-DMB) is 1.125 Mbps at1.536 MHz band.

Meanwhile, development of diverse services and contents producesservices of a new concept such as a data broadcasting service, anon-real time (NRT) service, a disaster alert service and so forth. Thiscalls for technical schemes that can support and transmit the additionalservices. Conventional broadcasting-communication system uses a methodof reducing the data transmission rates of an original service andallocating a new service to the reserved data transmission rate. Inother words, some of the bandwidth to be allocated to the originalservice is allocated to an additional service. As a result, thebandwidth to be allocated to the original service is reduced. In an ATSC8-VSB system, among 19.39 Mbps allocated to a High-Definition (HD)broadcasting, about 2 Mbps is allocated to a new additional service suchas a data broadcasting, and the remaining 17.4 Mbps is allocated to theoriginal HD broadcasting service. Since this method reduces the datatransmission rate of the original service to transmit the new additionalservice, there is a drawback in that the quality of the original serviceis deteriorated. Therefore, it is required to develop a datatransmission method that can transmit additional data without affectingthe transmission of original data.

DISCLOSURE Technical Problem

An embodiment of the present invention is directed to providing a methodand apparatus that can improve the overall transmission efficiency of asystem by transmitting new additional data while maintaining the datatransmission rate of original data.

Other objects and advantages of the present invention can be understoodby the following description, and become apparent with reference to theembodiments of the present invention. Also, it is obvious to thoseskilled in the art of the present invention that the objects andadvantages of the present invention can be realized by the means asclaimed and combinations thereof.

Technical Solution

In accordance with an aspect of the present invention, there is providedan apparatus for transmitting broadcasting-communication data includingoriginal data and additional data, which includes: an original signalgenerator configured to receive the original data and generate basebandoriginal signals; a first modulator configured to receive the basebandadditional signals and generate original signals of a predeterminedband; an additional signal generator configured to receive theadditional data and generate baseband additional signals; a secondmodulator configured to receive the baseband additional signals andgenerate additional signals of a predetermined band; an average powercontroller configured to control an average power of the additionalsignals of the predetermined band; an inserter configured to insert theadditional signals of the predetermined band with a controlled averagepower to the original signals of the predetermined band to therebygenerate mixed signals of a predetermined band; and a transmitterconfigured to transmit the mixed signals of the predetermined band.

In accordance with another aspect of the present invention, there isprovided an apparatus for transmitting broadcasting-communication dataincluding original data and additional data, which includes: an originalsignal generator configured to receive the original data and generatebaseband original signals; an additional signal generator configured toreceive the additional data and generate baseband additional signals; anaverage power controller configured to control an average power of thebaseband additional signals; an inserter configured to insert thebaseband additional signals with a controlled average power to thebaseband original signals to thereby generate baseband mixed signals; amodulator configured to receive the baseband mixed signals and generatemixed signals of a predetermined band; and a transmitter configured totransmit the mixed signals of the predetermined band.

In accordance with another aspect of the present invention, there isprovided a method for transmitting broadcasting-communication dataincluding original data and additional data, which includes: receivingthe original data and generating baseband original signals; receivingthe baseband original signals and generating original signals of apredetermined band; receiving the additional data and generatingbaseband additional signals; receiving the baseband additional signalsand generating additional signals of a predetermined band; controllingan average power of the additional signals of the predetermined band;inserting the additional signals of the predetermined band with acontrolled average power to the original signals of the predeterminedband to thereby generate mixed signals of a predetermined band; andtransmitting the mixed signals of the predetermined band.

In accordance with another aspect of the present invention, there isprovided a method for transmitting broadcasting-communication dataincluding original data and additional data, which includes: receivingthe original data and generating baseband original signals; receivingthe additional data and generating baseband additional signals;controlling an average power of the baseband additional signals;inserting the baseband additional signals with a controlled averagepower to the baseband original signals to thereby generate basebandmixed signals; receiving the baseband mixed signals and generating mixedsignals of a predetermined band; and transmitting the mixed signals ofthe predetermined band.

In accordance with another aspect of the present invention, there isprovided a broadcasting-communication data receiving apparatus forreceiving mixed signals including original signals and additionalsignals, which includes: a receiver configured to receive the mixedsignals and output mixed signals of a predetermined band; a firstdemodulator configured to receive the mixed signals of the predeterminedband and generate baseband mixed signals; an original data generatorconfigured to receive the baseband mixed signals and generate originaldata; an original signal generator configured to receive the originaldata and generate baseband original signals; a modulator configured toreceive the baseband original signals and generate original signals of apredetermined band; a subtractor configured to subtract the originalsignals of the predetermined band from the mixed signals of thepredetermined band to thereby generate additional signals of apredetermined band; a second demodulator configured to receive theadditional signals of the predetermined band and generate basebandadditional signals; and an additional data generator configured toreceive the baseband additional signals and generate additional data.

In accordance with another aspect of the present invention, there isprovided a broadcasting-communication data receiving apparatus forreceiving mixed signals including original signals and additionalsignals, which includes: a receiver configured to receive the mixedsignals and output mixed signals of a predetermined band; a demodulatorconfigured to receive the mixed signals of the predetermined band andgenerate baseband mixed signals; an original data generator configuredto receive the baseband mixed signals and generate original data; anoriginal signal generator configured to receive the original data andgenerate baseband original signals; a subtractor configured to subtractthe baseband original signals from the baseband mixed signals to therebygenerate baseband additional signals; and an additional data generatorconfigured to receive the baseband additional signals and generateadditional data.

In accordance with another aspect of the present invention, there isprovided a broadcasting-communication data receiving method forreceiving mixed signals including original signals and additionalsignals, which includes: receiving the mixed signals and outputtingmixed signals of a predetermined band; receiving the mixed signals ofthe predetermined band and generating baseband mixed signals; receivingthe baseband mixed signals and generating original data; receiving theoriginal data and generating baseband original signals; receiving thebaseband original signals and generating original signals of apredetermined band; subtracting the original signals of thepredetermined band from the mixed signals of the predetermined band tothereby generate additional signals of a predetermined band; receivingthe additional signals of the predetermined band and generating basebandadditional signals; and receiving the baseband additional signals andgenerating additional data.

In accordance with another aspect of the present invention, there isprovided a broadcasting-communication data receiving method forreceiving mixed signals including original signals and additionalsignals, which includes: receiving the mixed signals and outputtingmixed signals of a predetermined band; receiving the mixed signals ofthe predetermined band and generating baseband mixed signals; receivingthe baseband mixed signals and generating original data; receiving theoriginal data and generating baseband original signals; subtracting thebaseband original signals from the baseband mixed signals to therebygenerate baseband additional signals; and receiving the basebandadditional signals and generating additional data.

Advantageous Effects

The technology of the present invention described above can improve theoverall transmission efficiency of a system by transmitting newadditional data while maintaining the data transmission rate of originaldata.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block view of a broadcasting-communication data transmittingapparatus in accordance with an embodiment of the present invention.

FIG. 2 is a block view of a broadcasting-communication data transmittingapparatus in accordance with another embodiment of the presentinvention.

FIG. 3 is a block view of an original signal generator shown in FIGS. 1and 2.

FIG. 4 is a block view of an additional signal generator shown in FIGS.1 and 2.

FIG. 5 is a block view of a Forward Error Correction (FEC) encoder shownin FIG. 4.

FIG. 6 shows an orthogonal sequence generated in a spreading sequencegenerator shown in FIG. 4.

FIG. 7 is a block view of an average power controller shown in FIG. 1.

FIG. 8 is a block view of an average power controller shown in FIG. 2.

FIG. 9 is a block view illustrating a broadcasting-communication datatransmitting apparatus based on the Advanced Terrestrial SystemsCommittee (ATSC) 8-Vestigial Sideband (VSB) in accordance with yetanother embodiment of the present invention.

FIG. 10 is a block view describing a broadcasting-communication datareceiving apparatus in accordance with a first embodiment of the presentinvention.

FIG. 11 is a block view describing a broadcasting-communication datareceiving apparatus in accordance with a second of the presentinvention.

FIG. 12 is a block view describing a broadcasting-communication datareceiving apparatus in accordance with a third embodiment of the presentinvention.

FIG. 13 is a block view describing a broadcasting-communication datareceiving apparatus in accordance with a fourth embodiment of thepresent invention.

FIG. 14 is a block view describing an original data generator shown inFIGS. 10 to 13.

FIG. 15 is a block view describing an additional data generator shown inFIGS. 10 to 13.

FIG. 16 shows an orthogonal sequence generated in a despreading sequencegenerator shown in FIG. 15.

FIG. 17 is a block view of a correlator shown in FIG. 15.

FIG. 18 is a block view of an FEC decoder shown in FIG. 15.

FIG. 19 is a block view illustrating a broadcasting-communicationreceiving apparatus based on the ATSC 8-VSB standard in accordance witha fifth embodiment of the present invention.

BEST MODE FOR THE INVENTION

The advantages, features and aspects of the invention will becomeapparent from the following description of the embodiments withreference to the accompanying drawings, which is set forth hereinafter.When it is considered that detailed description on a prior art mayobscure a point of the present invention, the description will not beprovided. Hereafter, specific embodiments of the present invention willbe described in detail with reference to the accompanying drawings. Thesame reference numerals are given to the same constituent elements,although they appear in different drawings.

Hereafter, broadcasting or communication data that used to be providedto users will be referred to as original data, and data to be providedadditionally to the users other than the original data will be referredto as additional data.

FIG. 1 is a block view of a broadcasting-communication data transmittingapparatus in accordance with an embodiment of the present invention.Referring to FIG. 1, the broadcasting-communication data transmittingapparatus includes an original signal generator 102, a first modulator104, an additional signal generator 106, a second modulator 108, anaverage power controller 110, an additional data inserter 112, and atransmitter 114.

The original signal generator 102 receives original data and generatesbaseband original signals in conformity with the transmission standardof a broadcasting-communication system. The first modulator 104 receivesthe baseband original signals generated in the original signal generator102 and modulates them into original signals of a predetermined band.

The additional signal generator 106 receives additional data andgenerates baseband additional signals in conformity with thetransmission standard of the broadcasting-communication system. Thesecond modulator 108 receives the baseband additional signals generatedin the additional signal generator 106 and modulates them intoadditional signals of a predetermined band.

The average power controller 110 controls the average power of theadditional signals of the predetermined band generated in the secondmodulator 108. Herein, the reason why the average power of theadditional signals of the predetermined band is controlled is that theadditional signals of the predetermined band are band-spread andinserted in the form of noise, which scarcely affects the originalsignals of the predetermined band. Therefore, the average powercontroller 110 controls the average power of the additional signals ofthe predetermined band as long as the original signals are not affected.

The additional data inserter 112 inserts the additional signals of thepredetermined band whose average power is controlled by the averagepower controller 110 into the original signals of the predetermined bandgenerated in the first modulator 104 to thereby generate mixed signalsof a predetermined band including the original signals and theadditional signals mixed with each other.

The transmitter 114 transmits the mixed signals of the predeterminedband generated in the additional data inserter 112. If necessary, thetransmitter 114 may convert the mixed signals of the predetermined bandinto radio frequency (RF) band, which is appropriate for wirelesstransmission.

FIG. 2 is a block view of a broadcasting-communication data transmittingapparatus in accordance with another embodiment of the presentinvention. Referring to FIG. 2, the broadcasting-communication datatransmitting apparatus includes an original signal generator 202, anadditional signal generator 204, an average power controller 206, aninserter 208, a modulator 210, and a transmitter 212.

The original signal generator 202 receives original data and generatesbaseband original signals in conformity with the transmission standardof a broadcasting-communication system. The additional signal generator204 receives the additional signals and generates baseband additionalsignals in conformity with the transmission standard of thebroadcasting-communication system.

The average power controller 206 controls the average power of thebaseband additional signals generated in the additional signal generator204.

The inserter 208 inserts the additional signals of the predeterminedband whose average power is controlled by the average power controller206 into the original signals of the predetermined band generated in theoriginal signal generator 202 to thereby produce baseband mixed signals.

The modulator 210 receives the baseband mixed signals generated in theinserter 208 and modulates them into mixed signals of a predeterminedband.

The transmitter 212 transmits the mixed signals of the predeterminedband generated in the modulator 210. If necessary, the transmitter 212may convert the mixed signals of the predetermined band into RF band,which is appropriate for wireless transmission.

Since the broadcasting-communication data transmitting apparatus of FIG.2 uses one modulator, it has lower hardware complexity than thestructure of FIG. 1. Also, since the insertion of the additional signalsinto the original signals is performed at baseband, it can be easilyrealized.

FIG. 3 is a block view of an original signal generator 102 or 202 shownin FIGS. 1 and 2.

The original signal generator 102 of FIG. 1 or the original signalgenerator 202 of FIG. 2 may be formed in various forms. FIG. 3 presentsan example. The drawings shows a block view of an original signalgenerator according to the Advanced Terrestrial Systems Committee (ATSC)8-Vestigial SideBand (VSB) transmission standard, where Moving PictureExperts Group (MPEG) 2 Transport Stream (TS) is used as original data.

As illustrated in FIG. 3, the original signal generator includes a datarandomizer 302, a Reed Solomon (RS) encoder 304, an interleaver 306, aTrellis Coded Modulation (TCM) encoder 308, and a multiplexer (MUX) 310.

The data randomizer 302 receives original data, e.g., MPEG-2 transportstream, and spreads the spectrum of the received original datathroughout the entire band. This is to prevent energy from beingconcentrated on a specific frequency.

The RS encoder 304, which has excellent burst error correctioncapability, decreases errors occurring in the randomized original dataoutputted from the data randomizer 302 by performing outer encoding. Theinterleaver 306 regularly rearranges the RS-encoded original data toprevent burst error.

The interleaved original data outputted from the interleaver 306 undergoinner encoding in the TCM encoder 308, which is a sort of convolutionalencoder. The inner-encoded original data obtained in the TCM encoder 308are multiplexed with a field synchronization signal and a segmentsynchronization signal in the multiplexer 310 to be converted intobaseband ATSC broadcasting signal.

The additional signal generator of the broadcasting-communication datatransmitting apparatus suggested in the embodiment of the presentinvention is not limited to the ATSC 8-VSB system shown in FIG. 3, anddiverse broadcasting-communication standards may be applied thereto.

FIG. 4 is a block view of an additional signal generator 106 and 204shown in FIGS. 1 and 2. Referring to FIG. 4, the additional signalgenerator includes a Forward Error Correction (FEC) encoder 402, aspreading sequence generator 404, and a spreader 406.

The FEC encoder 402 receives additional data and performs errorcorrection encoding onto the additional data. Herein, the additionaldata inputted to the FEC encoder 402 may be compressed through diversemethods, e.g., H.264 and MPEG-4, the compression method of theadditional data may be different according to the system standard andrequirements. Also, diverse error correction codes, such as turbo code,Low Density Parity Check (LDPC) code, and a concatenate code, may beused in the FEC encoder 402. The error correction code to be used in theFEC encoder 402 may become different as well according to the systemstandard and requirements.

The spreading sequence generator 404 generates orthogonal orquasi-orthogonal sequence for spreading the error correction-encodeddata obtained in the FEC encoder 402. The spreading sequence generator404 may generate an orthogonal sequence, such as Walsh sequence, or aquasi-orthogonal sequence, such as Gold sequence, Kasami sequence,Bose-Chadhuri-Hocquenghem (BCH) sequence. Whether to select theorthogonal sequence or the quasi-orthogonal sequence may be determinedbased on the system standard and requirements.

The spreader 406 maps the error correction-encoded additional dataobtained in the FEC encoder 402 to a spreading sequence generated in thespreading sequence generator 404. This process is referred to asspreading. The sampling frequency of the spreading sequence is N timesthe sampling frequency of the error correction-encoded additional datainputted to the spreader 406, where N is an integer. Therefore, thebaseband additional signals outputted from the spreader 406 have aspreading gain as much as dB. Herein, N denotes the length of thespreading sequence.

The FEC encoder 402, the spreading sequence generator 404, and thespreader 406 shown in FIG. 4 may be formed diversely according to thesystem standard and requirements.

The spreader 406 maps error correction-encoded additional data obtainedin the FEC encoder 402 to the spreading sequence generated in thespreading sequence generator 404. This process is referred to asspreading. The sampling frequency of the spreading sequence is N timesthe sampling frequency of the error correction-encoded additional datainputted to the spreader 406, N being an integer. Thus, the basebandadditional signals outputted from the spreader 406 come to have aspreading gain of 10·log₁₀N dB, where N denotes the length of thespreading sequence.

The FEC encoder 402, the spreading sequence generator 404, and thespreader 406 shown in FIG. 4 may be formed diversely according to thesystem standard and requirements.

FIG. 5 is a block view of the FEC encoder shown in FIG. 4. Asillustrated in FIG. 5, the FEC encoder 402 includes a BCH encoder 502, afirst interleaver 504, an LDPC encoder 506, and a second interleaver508.

The BCH encoder 502, which is a linear block encoder with excellentrandom error correction capability, receives the additional data andperforms outer encoding. The outer-encoded additional data obtained inthe BCH encoder 502 are interleaved in the first interleaver 504.

The LDPC encoder 506, which has excellent error correction capability,receives the interleaved additional data obtained in the firstinterleaver 504 and performs inner encoding. The inner-encodedadditional data obtained in the LDPC encoder 506 are interleaved againin the second interleaver 508 to thereby produce errorcorrection-encoded additional data.

FIG. 6 shows an orthogonal sequence generated in a spreading sequencegenerator 404 shown in FIG. 4.

The sequence shown in FIG. 6 is a Walsh sequence having a length of 8and generated in the spreading sequence generator 404 shown in FIG. 4.The Walsh sequence having a length of 8 includes 8 components W₀, W₁,W₂, W₃, W₄, W₅, W₆, W₇, as shown in FIG. 6, and the sequences areorthogonal to each other. The Walsh sequence satisfies the followingEquation 1.

$\begin{matrix}{{< W_{i}},{{W_{j}>={\sum\limits_{k = 0}^{7}{{W_{i}(k)} \cdot {W_{j}(k)}}}} = \left\{ \begin{matrix}8 & {i = j} \\0 & {i \neq j}\end{matrix} \right.}} & {{Eq}.\mspace{14mu} 1}\end{matrix}$

where W_(i)(k) denotes the k^(th) value of the i^(th) Walsh code W_(i).

A Walsh sequence having a length of N may be easily generated fromWalsh-Hadamard transformation of a Walsh sequence having a length of 2.

The following Tables 1 and 2 describe a spreading process performed inthe spreader 406 by using the Walsh sequence having a length of 8, thatis, the mapping of the error correction-encoded additional data into aspreading sequence.

TABLE 1 C(i) c(i + 1) Mapping Sequence 00 W₀ 01 W₁ 10 −W₀ 11 −W₁

The Table 1 describes a process of grouping the error correction-encodedadditional data obtained in the FEC encoder 402 by two bits (c(i),c(i+1)) and mapping the 2-bit groups to two Walsh sequences W₀ and W₁.Herein, c(i) denotes the Most Significant Bit (MSB), and c(i+1) denotesthe Least Significant Bit (LSB).

TABLE 2 C(i) c(i + 1) c(i + 2) c(i + 3) Mapping Sequence 0000 W₀ 0001 W₁0010 W₂ 0011 W₃ 0100 W₄ 0101 W₅ 0110 W₆ 0111 W₇ 1000 −W₇ 1001 −W₆ 1010−W₅ 1011 −W₄ 1100 −W₃ 1101 −W₂ 1110 −W₁ 1111 −W₀

The Table 2 describes a process of grouping the error correction-encodedadditional data obtained in the FEC encoder 402 by four bits (c(i),c(i+1), c(i+2), c(i+3)) and mapping the 4-bit groups to 8 Walshsequences W₀, W₁, W₂, W₃, W₄, W₅, W₆, W₇. Herein, c(i) denotes the MostSignificant Bit (MSB), and c(i+3) denotes the Least Significant Bit(LSB).

FIG. 7 is a block view of the average power controller 110 shown inFIG. 1. The average power controller 110 includes a first average powercalculator 702, a second average power calculator 704, an insertionlevel decider 706, and a multiplier 708.

The first average power calculator 702 receives original signals of apredetermined band outputted from the first modulator 104 and calculatesthe average power of the original signals. The second average powercalculator 704 receives additional signals of a predetermined bandoutputted from the second modulator 108 and calculates the average powerof the additional signals.

The insertion level decider 706 compares the average power of theoriginal signals of the predetermined band, which is obtained in thefirst average power calculator 702, with the average power of theadditional signals of the predetermined band, which is obtained in thesecond average power calculator 704, and decides an insertion level α.Herein, α is a constant used to make the average power of the additionalsignals of the predetermined band far lower than the average power ofthe original signals of the predetermined band.

The multiplier 708 multiples the additional signals of the predeterminedband outputted from the second modulator 108 by the insertion level αdecided in the insertion level decider 706. As a result, the additionalsignals of the predetermined band come to have an average power farlower than that of the original signals of the predetermined band.

FIG. 8 is a block view of the average power controller 206 shown in FIG.2. The average power controller 206 includes a first average powercalculator 802, a second average power calculator 804, an insertionlevel decider 806, and a multiplier 808.

The first average power calculator 802 receives baseband originalsignals outputted from the original signal generator 202 and calculatesthe average power of the baseband original signals. The second averagepower calculator 804 receives baseband additional signals outputted fromthe additional signal generator 204 and calculates the average power ofthe baseband additional signals.

The insertion level decider 806 compares the average power of theoriginal signals of the baseband, which is obtained in the first averagepower calculator 802, with the average power of the additional signalsof the baseband, which is obtained in the second average powercalculator 804, and decides an insertion level α.

The multiplier 808 multiples the baseband additional signals outputtedfrom the additional signal generator 204 by the insertion level αdecided in the insertion level decider 806. As a result, the basebandadditional signals come to have an average power far lower than that ofthe baseband original signals.

The average power controller appearing in the embodiments of FIGS. 7 and8 decides the insertion level by comparing the average power of thesignals with each other. This is no more than an embodiment and theinsertion levels may be decided through other methods. For example, theaverage power controller may decides an appropriate insertion level forthe average power of a corresponding signal based on a table includingrecords on the insertion levels suitable for each average power oforiginal signals and additional signals.

FIG. 9 is a block view illustrating a broadcasting-communication datatransmitting apparatus based on the ATSC 8-VSB standard in accordancewith yet another embodiment of the present invention.

Referring to FIG. 9, the broadcasting-communication data transmittingapparatus includes an original signal generator 902, an additionalsignal generator 914, an average power controller 930, an inserter 940,a modulator 942, and a transmitter 948.

The original signal generator 902 includes a data randomizer 904, a ReedSolomon (RS) encoder 906, an interleaver 908, a TCM encoder 910, and amultiplexer 912.

The additional signal generator 914 includes an FEC encoder 916, aspreader 926, and a Walsh sequence generator 928. Herein, the FECencoder 916 includes a BCH encoder 918, a first interleaver 920, an LDPCencoder 922, and a second interleaver 924.

The average power controller 930 includes a first average powercalculator 932, a second average power calculator 934, an insertionlevel decider 936, and a multiplier 938.

The modulator 942 includes a VSB modulator 944 and a pilot adder 946.

The transmitter 948 includes an RF up-converter 950, a high-poweramplifier 952, and a transmission antenna 954.

Hereafter, a data transmitting process of the broadcasting-communicationdata transmitting apparatus of FIG. 9 will be described. First, the datarandomizer 904 receives original data, e.g., MPEG-2 transport stream,and outputs randomized original data. The randomized original dataundergo error correction encoding in the RS encoder and then go throughinterleaving in the interleaver 908. The TCM encoder 910 receives theinterleaved original data and performs TCM inner encoding. Themultiplexer 912 multiplexes the inner-encoded original data togetherwith a field synchronization signal and a segment synchronization signaland converts them into baseband ATSC original signals.

Meanwhile, additional data compressed based on such a compression schemeas H.264 are outer-encoded in the BCH encoder 918 and interleaved in thefirst interleaver 920. The interleaved additional data obtained in thefirst interleaver 920 are inner-encoded in the LDPC encoder 922, andthen interleaved again in the second interleaver 924 to be transformedinto error correction-encoded additional data.

The Walsh sequence generator 928 included in the additional signalgenerator 914 generates a Walsh sequence having orthogonal property tospread the error correction-encoded additional data. The spreader 926maps the error correction-encoded additional data, which are outputtedfrom the FEC encoder 916, to the Walsh sequence generated in the Walshsequence generator 928.

The first average power calculator 932 included in the average powercontroller 930 calculates the average power of baseband ATSC originalsignals outputted from the multiplexer 912 of the original signalgenerator 902. The second average power calculator 934 calculates theaverage power of the baseband additional data outputted from thespreader 926.

The insertion level decider 936 compares the average powers outputtedfrom the first average power calculator 932 and the second average powercalculator 934 with each other and determines an insertion level α. Theinsertion level α is a constant that makes the average power of thebaseband additional signals far lower than the average power of thebaseband original signals.

The multiplier 938 controls the average power by multiplying thebaseband additional signals outputted from the spreader 926 by theinsertion level α decided in the insertion level decider 936.

The inserter 940 inserts the baseband additional signals with acontrolled average power into the baseband ATSC original signals, whichis expressed as the following Equation 2.

s(n)=d(n)+α·d′(n)  Eq. 2

where d(n) denotes a baseband ATSC original signal and may have a valueamong −7, −5, −3, −1, +1, +3, +5, and +7; d′(n) denotes a basebandadditional signal; a denotes the insertion level of the basebandadditional signal; and s(n) denotes a baseband mixed signal including anadditional signal inserted to an original signal.

The mixed signals generated in the inserter 940 are inputted to a pilotadder 946 included in the modulator 942. The pilot adder 946 adds apilot signal to a baseband mixed signal outputted from the inserter 940,which is expressed as the following Equation 3.

t(n)=s(n)+1.25  Eq. 3

where the number 1.25 denotes a pilot signal added to a mixed signals(n); and t(n) denotes a baseband mixed signal with a pilot signal addedthereto.

The VSB modulator 944 modulates the baseband mixed signals with a pilotsignal added thereto into VSB signals of a predetermined band.

The RF up-converter 950 included in the transmitter 948 up-converts theVSB-modulated mixed signals of the predetermined band into RF signals.The RF signals obtained in the RF up-converter 950 are amplified by thehigh-power amplifier 952 and wirelessly transmitted through thetransmission antenna 954.

In the above, the broadcasting-communication data transmitting apparatusand method according to the present invention have been described.Hereafter, a broadcasting-communication data receiving apparatus andmethod will be described.

FIG. 10 is a block view describing a broadcasting-communication datareceiving apparatus in accordance with a first embodiment of the presentinvention.

Referring to FIG. 10, the broadcasting-communication data receivingapparatus includes a receiver 1002, a first demodulator 1004, anoriginal data generator 1006, an original signal generator 1008, amodulator 1010, a subtractor 1012, a second demodulator 1014, and anadditional data generator 1016.

The receiver 1002 receives mixed signals including original signals andadditional signals mixed with each other, which are transmitted from abroadcasting-communication data transmitting apparatus. If necessary,the receiver 1002 may convert the mixed signals into mixed signals of apredetermined band.

The first demodulator 1004 receives mixed signals of a predeterminedband and generates baseband mixed signals. The original data generator1006 receives the baseband mixed signals outputted from the firstdemodulator 1004 and restores original data.

The original signal generator 1008 receives error correction-decodedoriginal data outputted from the original data generator 1006 andgenerates the baseband original signals without an additional signalagain. The modulator 1010 receives the baseband original signalsgenerated through the original signal generator 1008 and converts theminto the same band as the predetermined band of the mixed signalsoutputted from the receiver 1002.

The subtractor 1012 generates additional signals of a predetermined bandby subtracting the additional signals of the predetermined bandoutputted from the modulator 1010 from the mixed signals of thepredetermined band outputted from the receiver 1002.

The second demodulator 1014 receives the additional signals of thepredetermined band outputted from the subtractor 1012 and generatesbaseband additional signals. The additional data generator 1016 receivesthe baseband additional signals and restores the additional data.

FIG. 11 is a block view describing a broadcasting-communication datareceiving apparatus in accordance with a second of the presentinvention. Referring to FIG. 11, the broadcasting-communication datareceiving apparatus includes a receiver 1022, a first demodulator 1024,an original data generator 1026, a decider 1028, a modulator 1030, asubtractor 1032, a second demodulator 1034, and an additional datagenerator 1036.

The receiver 1022 receives mixed signals including original signals andadditional signals mixed with each other from abroadcasting-communication data transmitting apparatus. If necessary,the receiver 1022 may convert the mixed signals into mixed signals of apredetermined band.

The first demodulator 1024 receives the mixed signals of thepredetermined band and generates baseband mixed signals. The originaldata generator 1026 receives the baseband mixed signals outputted fromthe first demodulator 1024 and restores original data.

The decider 1028 receives the baseband mixed signals outputted from thefirst demodulator 1024 and makes a decision to have only basebandoriginal signals without additional signals. In other words, the decider1028 removes the components including the additional signals, other thanthe baseband original signals, and leaves only the baseband originalsignals of the baseband mixed signals outputted from the firstdemodulator 1024. For example, when an original signal component to betransmitted from a transmitting apparatus is an integer number ‘7’ andan additional signal is ‘0.2’ and noise occurring during thetransmission is ‘0.3,’ the mixed signal inputted to the decider 1028becomes 7.5. The decider 1028 removes ‘0.5’ from ‘7.5,’ leaving only theoriginal signal component ‘7.’

The modulator 1030 receives the baseband original signals of thepredetermined band decided in the decider 1028 and converts the basebandoriginal signals into the same band as the predetermined band of themixed signals outputted from the receiver 1022.

The subtractor 1032 generates additional signals of a predetermined bandby subtracting the original signals of the predetermined band outputtedfrom the modulator 1030 from the mixed signals of the predetermined bandoutputted from the receiver 1022.

The second demodulator 1034 receives the additional signals of thepredetermined band outputted from the subtractor 1032 and generatesbaseband additional signals. The additional data generator 1036 receivesthe baseband additional signals and restores additional signals.

The broadcasting-communication data receiving apparatus shown in FIGS.10 and 11 is appropriate for receiving mixed signals transmitted from atransmitting apparatus including a first modulator and a secondmodulator separately, like the broadcasting-communication datatransmitting apparatus shown in FIG. 1.

FIG. 12 is a block view describing a broadcasting-communication datareceiving apparatus in accordance with a third embodiment of the presentinvention. Referring to FIG. 12, the broadcasting-communication datareceiving apparatus includes a receiver 1102, a demodulator 1104, anoriginal data generator 1106, an original signal generator 1108, asubtractor 1110, and an additional data generator 1112.

The receiver 1102 receives mixed signals including original signals andadditional signals mixed with each other from abroadcasting-communication data transmitting apparatus. If necessary,the receiver 1102 may convert the mixed signals into mixed signals of apredetermined band.

The demodulator 1104 receives the mixed signals of the predeterminedband and generates baseband mixed signals.

The original data generator 1106 receives the baseband mixed signalsoutputted from the demodulator 1104 and restores original data.

The original signal generator 1108 receives error correction-decodedoriginal data outputted from the original data generator 1106 andgenerates baseband original signals without additional signals thereinagain.

The subtractor 1110 generates baseband additional signals by subtractingthe baseband original signals outputted from the original signalgenerator 1108 out of the baseband mixed signals outputted from thedemodulator 1104.

The additional data generator 1112 receives the baseband additionalsignals and restores additional signals.

FIG. 13 is a block view describing a broadcasting-communication datareceiving apparatus in accordance with a fourth embodiment of thepresent invention. Referring to FIG. 13, the broadcasting-communicationdata receiving apparatus includes a receiver 1122, a demodulator 1124,an original data generator 1126, a decider 1128, a subtractor 1130, andan additional data generator 1132.

The receiver 1122 receives mixed signals including original signals andadditional signals mixed with each other from abroadcasting-communication data transmitting apparatus. If necessary,the receiver 1122 may convert the mixed signals into mixed signals of apredetermined band.

The demodulator 1124 receives the mixed signals of the predeterminedband and generates baseband mixed signals.

The original data generator 1126 receives the baseband mixed signalsoutputted from the demodulator 1124 and restores original data.

The decider 1128 receives the baseband mixed signals outputted from thedemodulator 1124 and makes a decision to have only baseband originalsignals without additional signals. In other words, the decider 1128removes the components including the additional signals, other than thebaseband original signals, of the baseband mixed signals outputted fromthe demodulator 1124, and leaves only the baseband original signals.

The subtractor 1130 generates baseband additional signals by subtractingthe baseband original signals outputted from the decider 1128 out of thebaseband mixed signals outputted from the demodulator 1124.

The additional data generator 1132 receives the baseband additionalsignals and restores additional signals.

The broadcasting-communication data receiving apparatus shown in FIGS.12 and 13 is appropriate for receiving mixed signals transmitted from atransmitting apparatus including a single modulator 210, like thebroadcasting-communication data transmitting apparatus shown in FIG. 2.

FIG. 14 is a block view describing the original data generator shown inFIGS. 10 to 13. Referring to FIG. 14, the original data generatorincludes a TCM decoder 1202, a deinterleaver 1204, an RS decoder 1206,and a data derandomizer 1208.

The TCM decoder 1202 receives baseband original signals, e.g., basebandATSC broadcasting signals, and performs inner decoding on the basebandoriginal signals to thereby primarily remove noise included therein.

The deinterleaver 1204 receives the baseband original signals withoutnoise outputted from the TCM decoder 1202 and outputs deinterleavedbaseband original signals.

The RS decoder 1206 receives the deinterleaved baseband original signalsand performs outer decoding to thereby secondarily remove noise.

The data derandomizer 1208 receives the baseband original signalsoutputted from the RS decoder 1206 and derandomizes the basebandoriginal signal to thereby generate original data, e.g., MPEG-2transport stream.

The original data generator of the broadcasting-communication datareceiving apparatus of the present invention is not limited to the ATSC8-VSB system as shown in FIG. 14, and it may adopt diverse kinds ofbroadcasting-communication standards.

Particularly, according to the ATSC 8-VSB transmission standard, theoriginal signal generator of FIGS. 10 to 13 may transmit symbol-leveloutput signals outputted from the TCM decoder 1202 to the modulator 1010or the subtractor 1110. This is performed to prevent an ambiguityproblem of a TCM code. The ambiguity problem of a TCM code is aphenomenon that different outputs are acquired according to the state ofa memory although the same inputs are made. This occurs because theinitial state of a memory of a TCM encoder is not uniform.

FIG. 15 is a block view describing the additional data generator shownin FIGS. 10 to 13. Referring to FIG. 15, the additional data generatorincludes a correlator 1302, an FEC decoder 1304, and a despreadingsequence generator 1306.

The despreading sequence generator 1306 generates an orthogonal orquasi-orthogonal sequence for despreading baseband additional signalsinputted to the correlator 1302. The despreading sequence generator 1306may generate an orthogonal sequence, e.g., Walsh sequence, or aquasi-orthogonal sequence, e.g., Gold sequence, Kasami sequence, andBose-Chadhuri-Hocquenghem (BCH) sequence, which corresponds to thespreading sequence generator of the broadcasting-communication datatransmitting apparatus of the present invention. Whether to select anorthogonal sequence or a quasi-orthogonal sequence may depend on thesystem standard and requirements.

The correlator 1302 calculates correlation values by correlating theinputted baseband additional signals with the despreading sequencegenerated in the despreading sequence generator 1306 and selects thelargest correlation value among the correlation values. Therefore, theadditional signals outputted from the correlator 1302 come to have aspreading gain as much as 10·log₁₀N dB due to the correlation, where Ndenotes the length of the despreading sequence.

The FEC decoder 1304 removes noise caused during the signal transmissionfrom the baseband additional signals having the spreading gain as muchas 10·log₁₀N dB and outputted from the correlator 1302. Herein, the FECdecoder 1304 may use diverse error correction codes, such as a turbocode, an LDPC code, a concatenate code and so forth. The errorcorrection code may be selected according to the system standard andrequirements.

The correlator 1302, the FEC decoder 1304, and the despreading sequencegenerator 1306 may be formed diversely according to the system standardand requirements.

FIG. 16 shows an orthogonal sequence generated in the despreadingsequence generator 1306 shown in FIG. 15.

The spreading sequence shown in FIG. 16 is a Walsh sequence having alength of 8. The Walsh sequence having a length of 8 includes 8components W₀, W₁, W₂, W₃, W₄, W₅, W₆, W₇, and the sequences areorthogonal to each other. The Walsh sequence satisfies the followingEquation 4.

$\begin{matrix}{{< W_{i}},{{W_{j}>={\sum\limits_{k = 0}^{7}{{W_{i}(k)} \cdot {W_{j}^{*}(k)}}}} = \left\{ \begin{matrix}8 & {i = j} \\0 & {i \neq j}\end{matrix} \right.}} & {{Eq}.\mspace{14mu} 4}\end{matrix}$

where W_(i)(k) denotes the k^(th) value of the i^(th) Walsh code; and *denotes a conjugate.

A Walsh sequence having a length of N may be easily generated fromWalsh-Hadamard transformation of a Walsh sequence having a length of 2.

FIG. 17 is a block view of the correlator 1302 shown in FIG. 15.Referring to FIG. 17, the correlator 1302 includes a correlation valuecalculator 1502 and a correlation value selector 1504.

The correlation value calculator 1502 multiples the baseband additionalsignals by conjugates of the sequences W₀, W₁, W₂, W₃, W₄, W₅, W₆, W₇generated in the despreading sequence generator 1306, which is adespreading process, and calculates correlation values R₀, R₁, R₂, R₃,R₄, R₅, R₆ and R₇ through a sum-and-dump process.

The correlation value selector 1504 selects one whose absolute value isthe largest among the correlation values R₀, R₁, R₂, R₃, R₄, R₅, R₆ andR₇ obtained in the correlation value calculator 1502, and the sign forthe value follows the sign of the value before the value takes on theabsolute mark. The output of the correlation value selector 1504 isexpressed as the following Equation 5.

Output of correlator=sgn(R _(i) _(max) )·|R _(i) _(max) |=R _(i) _(MAX)  Eq. 5

Herein, sgn( ) and ∥ denote a sign and an absolute value, respectively,and i_(max) denotes the index of the largest value among the absolutevalues of the correlation values. The i_(max) is expressed as thefollowing Equation 6.

i _(max) =arg _(i) max|R _(i)  Eq. 6

FIG. 18 is a block view of the FEC decoder 1304 shown in FIG. 15.Referring to FIG. 18, the FEC decoder 1304 includes a seconddeinterleaver 1602, an LDPC decoder 1604, a first deinterleaver 1606,and a BCH decoder 1608.

The second deinterleaver 1602 receives the baseband additional signalshaving a spreading gain, which are outputted from the correlator 1302and outputs deinterleaved baseband additional signals. The LDPC decoder1604 receives the deinterleaved baseband additional signals obtained inthe second deinterleaver 1602 and primarily removes noise caused duringa transmission process.

The first deinterleaver 1606 receives the additional signals withoutnoise, which are obtained in the LDPC decoder 1604 and outputsdeinterleaved additional signals. The BCH decoder 1608 receives thedeinterleaved additional signals obtained in the first deinterleaver1606, secondarily removes the noise caused in the transmission process,and generates error correction-decoded additional data.

FIG. 19 is a block view illustrating a broadcasting-communicationreceiving apparatus based on the ATSC 8-VSB standard in accordance witha fifth embodiment of the present invention. Referring to FIG. 19, thebroadcasting-communication receiving apparatus includes a receiver 1702,a demodulator 1708, an original data generator 1714, a subtractor 1724,and an additional data generator 1726.

The receiver 1702 includes a reception antenna 1704 and a tuner 1706.Also, the demodulator 1708 includes a VSB demodulator 1710 and anequalizer 1712. The original data generator 1714 includes a TCM decoder1716, a deinterleaver 1718, an RS decoder 1720, and a data derandomizer1722.

The additional data generator 1726 includes a correlator 1728, adespreading sequence generator 1730, and an FEC decoder 1732.

The FEC decoder 1732 includes a second deinterleaver 1734, an LDPCdecoder 1736, a first deinterleaver 1738, and a BCH decoder 1740.

Hereafter, a data receiving method of the broadcasting-communicationdata receiving apparatus shown in FIG. 19 will be described in detail.First, the reception antenna 1704 receives mixed signals includingoriginal signals and additional signals mixed with each other from abroadcasting-communication data transmitting apparatus. The mixedsignals are converted into mixed signals of a predetermined band throughthe tuner 1706 included in the receiver 1702.

The VSB demodulator 1710 receives the mixed signals of the predeterminedband outputted from the tuner 1706 and converts them into baseband mixedsignals. The equalizer 1712 receives the baseband mixed signals andremoves multi-path signals generated during a transmission process.

The TCM decoder 1716 primarily removes the noise caused during thetransmission process out of the baseband mixed signals without themulti-path signals, which are obtained in the equalizer 1712. Thedeinterleaver 1718 deinterleaves the baseband mixed signals with noiseprimarily removed.

The RS decoder 1720 secondarily removes noise caused during thetransmission process out of the deinterleaved mixed signals. The dataderandomizer 1722 derandomizes the baseband mixed signals without noiseobtained from the RS decoder 1720 and generates original data, e.g.,MPEG-2 transport stream.

Meanwhile, the subtractor 1724 subtracts symbol-level output signals ofthe TCM decoder 1716, which correspond to the original signals, from thebaseband mixed signals outputted from the equalizer 1712 to therebyleave only baseband additional signals.

The despreading sequence generator 1730 generates an orthogonal orquasi-orthogonal sequence for despreading the baseband additionalsignals outputted from the subtractor 1724. The correlator 1728calculates correlation values by correlating the despreading sequencegenerated in the despreading sequence generator 1730 with the basebandadditional signals outputted from the subtractor 1724, and selects thelargest correlation value among the correlation values.

The baseband additional signals having a spreading gain outputted fromthe correlator 1728 are deinterleaved in the second deinterleaver 1734.The LDPC decoder 1736 decodes the deinterleaved additional signals tothereby primarily remove noise caused during the transmission process.

The first deinterleaver 1738 deinterleaves the output signals of theLDPC decoder 1736. The BCH decoder 1740 secondarily removes noise fromthe deinterleaved baseband additional signals outputted from the firstdeinterleaver 1738 to thereby generate error correction-decodedadditional data.

The apparatus and method of the present invention described above isadvantageous in that it can improve the overall transmission efficiencyof a system by transmitting new additional data while maintaining thedata transmission rate of original data. In short, the apparatus andmethod of the present invention can transmit/receive additional datawhile maintaining the bandwidth for transmitting original data andcompatibility with conventional data transmission/reception systems.

Particularly, when data are transmitted, the apparatus and method of thepresent invention can easily separate original signals and additionalsignals from each other in the receiving part, compared to the priorart, because additional signals are inserted to original data bycontrolling the average power of the additional data. Also, the datatransmission/reception method of the present invention can transmit moreadditional data than the prior art, which is advantageous as well.

The broadcasting-communication data transmitting/receiving method andapparatus of the present invention described above is appropriate forbroadcasting systems, e.g., ATSC, DVB, DMB, ISDB-T, and communicationsystems, e.g., WiBro, but it is not limited to them and it can beapplied to any environments requiring general additional datatransmission.

While the present invention has been described with respect to thespecific embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirit and scope of the invention as defined in the followingclaims.

What is claimed is:
 1. A broadcasting-communication data receivingapparatus for receiving mixed signals including original signals andadditional signals, comprising: a receiver configured to receive themixed signals and output mixed signals of a predetermined band; a firstdemodulator configured to receive the mixed signals of the predeterminedband and generate baseband mixed signals; an original data generatorconfigured to receive the baseband mixed signals and generate originaldata; an original signal generator configured to receive the originaldata and generate baseband original signals; a modulator configured toreceive the baseband original signals and generate original signals of apredetermined band; a subtractor configured to subtract the originalsignals of the predetermined band from the mixed signals of thepredetermined band to thereby generate additional signals of apredetermined band; a second demodulator configured to receive theadditional signals of the predetermined band and generate basebandadditional signals; and an additional data generator configured toreceive the baseband additional signals and generate additional data. 2.The broadcasting-communication data receiving apparatus of claim 1,wherein the original data generator includes: an inner decoderconfigured to receive the baseband mixed signals and outputinner-decoded baseband mixed signals; a deinterleaver configured toreceive the inner-decoded baseband mixed signals and outputdeinterleaved baseband mixed signals; an outer decoder configured toreceive the deinterleaved baseband mixed signals and outputouter-decoded baseband mixed signals; and a derandomizer configured togenerate original data by receiving and derandomizing the outer-decodedbaseband mixed signals.
 3. The broadcasting-communication data receivingapparatus of claim 1, wherein the additional data generator includes: adespreading sequence generator configured to generate an orthogonal orquasi-orthogonal sequence; a correlator configured to calculatecorrelation values between the baseband additional signals and thedespreading sequence, select a largest correlation value, and outputbaseband additional signals having a spreading gain by the largestcorrelation value; and a first decoder configured to remove noise fromthe baseband additional signals outputted from the correlator.
 4. Thebroadcasting-communication data receiving apparatus of claim 3, whereinthe decoder includes: a deinterleaver configured to receive the basebandadditional signals outputted from the correlator and outputdeinterleaved baseband additional signals; and a noise removing decoderconfigured to remove noise from the deinterleaved baseband additionalsignals obtained in the deinterleaver.
 5. A broadcasting-communicationdata receiving apparatus for receiving mixed signals including originalsignals and additional signals, comprising: a receiver configured toreceive the mixed signals and output mixed signals of a predeterminedband; a first demodulator configured to receive the mixed signals of thepredetermined band and generate baseband mixed signals; an original datagenerator configured to receive the baseband mixed signals and generateoriginal data; a decider configured to generate baseband originalsignals by removing components other than the baseband original signalsfrom the baseband mixed signals; a modulator configured to receive thebaseband original signals and generate original signals of apredetermined band; a subtractor configured to subtract the originalsignals of the predetermined band from the mixed signals of thepredetermined band to thereby generate additional signals of apredetermined band; a second demodulator configured to receive theadditional signals of the predetermined band and generate basebandadditional signals; and an additional data generator configured toreceive the baseband additional signals and generate additional data. 6.A broadcasting-communication data receiving apparatus for receivingmixed signals including original signals and additional signals,comprising: a receiver configured to receive the mixed signals andoutput mixed signals of a predetermined band; a demodulator configuredto receive the mixed signals of the predetermined band and generatebaseband mixed signals; an original data generator configured to receivethe baseband mixed signals and generate original data; an originalsignal generator configured to receive the original data and generatebaseband original signals; a subtractor configured to subtract thebaseband original signals from the baseband mixed signals to therebygenerate baseband additional signals; and an additional data generatorconfigured to receive the baseband additional signals and generateadditional data.
 7. A broadcasting-communication data receivingapparatus for receiving mixed signals including original signals andadditional signals, comprising: a receiver configured to receive themixed signals and output mixed signals of a predetermined band; ademodulator configured to receive the mixed signals of the predeterminedband and generate baseband mixed signals; an original data generatorconfigured to receive the baseband mixed signals and generate originaldata; a decider configured to generate baseband original signals byremoving components other than the baseband original signals from thebaseband mixed signals; a subtractor configured to subtract the basebandoriginal signals from the baseband mixed signals to thereby generatebaseband additional signals; and an additional data generator configuredto receive the baseband additional signals and generate additional data.8. A broadcasting-communication data receiving method for receivingmixed signals including original signals and additional signals,comprising: receiving the mixed signals and outputting mixed signals ofa predetermined band; receiving the mixed signals of the predeterminedband and generating baseband mixed signals; receiving the baseband mixedsignals and generating original data; receiving the original data andgenerating baseband original signals; receiving the baseband originalsignals and generating original signals of a predetermined band;subtracting the original signals of the predetermined band from themixed signals of the predetermined band to thereby generate additionalsignals of a predetermined band; receiving the additional signals of thepredetermined band and generating baseband additional signals; andreceiving the baseband additional signals and generating additionaldata.